spring 3.0 應用springmvc 構造RESTful URL 詳細講解

http://www.blogjava.net/badqiu/archive/2009/09/22/296082.html

由於下一版本的rapid-framwork需要集成spring RESTful URL,所以研究了一下怎麼搭建. 並碰到了一下問題。

 

springmvc 3.0 中增加 RESTful URL功能，構造出類似javaeye現在的URL。 rest介紹
比如如下URL

/blog/1  HTTP GET =>    得到id = 1的blog
/blog/1  HTTP DELETE => 刪除 id = 1的blog
/blog/1  HTTP PUT  =>   更新id = 1的blog
/blog     HTTP POST =>   新增BLOG

 

 

以下詳細解一下spring rest使用.

 

首先，我們帶着如下三個問題查看本文。

1. 如何在java構造沒有擴展名的RESTful url,如 /forms/1,而不是 /forms/1.do

2. 由於我們要構造沒有擴展名的url本來是處理靜態資源的容器映射的，現在被我們的spring佔用了，衝突怎麼解決?

3. 瀏覽器的form標籤不支持提交delete,put請求，如何曲線解決?

 

springmvc rest 實現

springmvc的resturl是通過@RequestMapping 及@PathVariable annotation提供的,通過如@RequestMapping(value="/blog/{id}",method=RequestMethod.DELETE)即可處理/blog/1 的delete請求.

@RequestMapping(value="/blog/{id}",method=RequestMethod.DELETE)
public ModelAndView delete(@PathVariable Long id,HttpServletRequest request,HttpServletResponse response) {
    blogManager.removeById(id);
    return new ModelAndView(LIST_ACTION);
}

 

@RequestMapping @PathVariable如果URL中帶參數，則配合使用，如

@RequestMapping(value="/blog/{blogId}/message/{msgId}",method=RequestMethod.DELETE)
public ModelAndView delete(@PathVariable("blogId") Long blogId,@PathVariable("msgId") Long msgId,HttpServletRequest request,HttpServletResponse response) {
}

 

 spring rest配置指南

1. springmvc web.xml配置

<!-- 該servlet爲tomcat,jetty等容器提供,將靜態資源映射從/改爲/static/目錄，如原來訪問 http://localhost/foo.css ,現在http://localhost/static/foo.css -->
<servlet-mapping>
    <servlet-name>default</servlet-name>
    <url-pattern>/static/*</url-pattern>
</servlet-mapping>
<servlet>
    <servlet-name>springmvc</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <load-on-startup>1</load-on-startup>
</servlet>

<!-- URL重寫filter,用於將訪問靜態資源http://localhost/foo.css 轉爲http://localhost/static/foo.css -->
<filter>
    <filter-name>UrlRewriteFilter</filter-name>
    <filter-class>org.tuckey.web.filters.urlrewrite.UrlRewriteFilter</filter-class>
    <init-param>
            <param-name>confReloadCheckInterval</param-name>
            <param-value>60</param-value>
        </init-param>
    <init-param>
                <param-name>logLevel</param-name>
                <param-value>DEBUG</param-value>
        </init-param>
</filter>
<filter-mapping>
    <filter-name>UrlRewriteFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

<!-- 覆蓋default servlet的/, springmvc servlet將處理原來處理靜態資源的映射 -->
<servlet-mapping>
    <servlet-name>springmvc</servlet-name>
    <url-pattern>/</url-pattern>
</servlet-mapping>

<!-- 瀏覽器不支持put,delete等method,由該filter將/blog?_method=delete轉換爲標準的http delete方法 -->
<filter>
    <filter-name>HiddenHttpMethodFilter</filter-name>
    <filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>
</filter>

<filter-mapping>
    <filter-name>HiddenHttpMethodFilter</filter-name>
    <servlet-name>springmvc</servlet-name>
</filter-mapping>

 

 

2. webapp/WEB-INF/springmvc-servlet.xml配置,使用如下兩個class激活@RequestMapping annotation

<bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping"/>
<bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"/>

 

完整配置

<beans default-autowire="byName"   >

    <!-- 自動搜索@Controller標註的類 -->
    <context:component-scan base-package="com.**.controller"/>

    <bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping"/>

    <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"/>

    <!-- Default ViewResolver -->
    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
        <property name="prefix" value="/pages"/>
        <property name="suffix" value=".jsp"></property>
    </bean>

    <bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource" p:basename="i18n/messages"/>

    <!-- Mapping exception to the handler view -->
    <bean id="exceptionResolver" class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
        <!-- to /commons/error.jsp -->
        <property name="defaultErrorView" value="/commons/error"/>
        <property name="exceptionMappings">
            <props>
            </props>
        </property>
    </bean>

</beans>

 

 

3. Controller編寫

/**
 * @RequestMapping("/userinfo") 具有層次關係，方法級的將在類一級@RequestMapping之一,
 * 如下面示例, 訪問方法級別的@RequestMapping("/new"),則URL爲 /userinfo/new
 */
@Controller
@RequestMapping("/userinfo")
public class UserInfoController extends BaseSpringController{
    //默認多列排序,example: username desc,createTime asc
    protected static final String DEFAULT_SORT_COLUMNS = null;

    private UserInfoManager userInfoManager;

    private final String LIST_ACTION = "redirect:/userinfo";

    /**
     * 通過spring自動注入
     **/
    public void setUserInfoManager(UserInfoManager manager) {
        this.userInfoManager = manager;
    }

    /** 列表 */
    @RequestMapping
    public ModelAndView index(HttpServletRequest request,HttpServletResponse response,UserInfo userInfo) {
        PageRequest<Map> pageRequest = newPageRequest(request,DEFAULT_SORT_COLUMNS);
        //pageRequest.getFilters(); //add custom filters

        Page page = this.userInfoManager.findByPageRequest(pageRequest);
        savePage(page,pageRequest,request);
        return new ModelAndView("/userinfo/list","userInfo",userInfo);
    }

    /** 進入新增 */
    @RequestMapping(value="/new")
    public ModelAndView _new(HttpServletRequest request,HttpServletResponse response,UserInfo userInfo) throws Exception {
        return new ModelAndView("/userinfo/new","userInfo",userInfo);
    }

    /** 顯示 */
    @RequestMapping(value="/{id}")
    public ModelAndView show(@PathVariable Long id,HttpServletRequest request,HttpServletResponse response) throws Exception {
        UserInfo userInfo = (UserInfo)userInfoManager.getById(id);
        return new ModelAndView("/userinfo/show","userInfo",userInfo);
    }

    /** 編輯 */
    @RequestMapping(value="/{id}/edit")
    public ModelAndView edit(@PathVariable Long id,HttpServletRequest request,HttpServletResponse response) throws Exception {
        UserInfo userInfo = (UserInfo)userInfoManager.getById(id);
        return new ModelAndView("/userinfo/edit","userInfo",userInfo);
    }

    /** 保存新增 */
    @RequestMapping(method=RequestMethod.POST)
    public ModelAndView create(HttpServletRequest request,HttpServletResponse response,UserInfo userInfo) throws Exception {
        userInfoManager.save(userInfo);
        return new ModelAndView(LIST_ACTION);
    }

    /** 保存更新 */
    @RequestMapping(value="/{id}",method=RequestMethod.PUT)
    public ModelAndView update(@PathVariable Long id,HttpServletRequest request,HttpServletResponse response) throws Exception {
        UserInfo userInfo = (UserInfo)userInfoManager.getById(id);
        bind(request,userInfo);
        userInfoManager.update(userInfo);
        return new ModelAndView(LIST_ACTION);
    }

    /** 刪除 */
    @RequestMapping(value="/{id}",method=RequestMethod.DELETE)
    public ModelAndView delete(@PathVariable Long id,HttpServletRequest request,HttpServletResponse response) {
        userInfoManager.removeById(id);
        return new ModelAndView(LIST_ACTION);
    }

    /** 批量刪除 */
    @RequestMapping(method=RequestMethod.DELETE)
    public ModelAndView batchDelete(@RequestParam("items") Long[] items,HttpServletRequest request,HttpServletResponse response) {

        for(int i = 0; i < items.length; i++) {

            userInfoManager.removeById(items[i]);
        }
        return new ModelAndView(LIST_ACTION);
    }

}

 

 

上面是rapid-framework 新版本生成器生成的代碼,以後也將應用此規則,rest url中增刪改查等基本方法與Controller的方法映射規則

/userinfo           => index()
/userinfo/new       => _new()
/userinfo/{id}      => show()
/userinfo/{id}/edit         => edit()
/userinfo   POST        => create()
/userinfo/{id}  PUT => update()
/userinfo/{id}  DELETE  => delete()
/userinfo   DELETE      => batchDelete()

 注(不使用 /userinfo/add  => add() 方法是由於add這個方法會被maxthon瀏覽器當做廣告鏈接過濾掉,因爲包含ad字符)

 

4. jsp 編寫

<form:form action="${ctx}/userinfo/${userInfo.userId}" method="put">
</form:form>

 生成的html內容如下, 生成一個hidden的_method=put,並於web.xml中的HiddenHttpMethodFilter配合使用，在服務端將post請求改爲put請求

<form id="userInfo" action="/springmvc_rest_demo/userinfo/2" method="post">
    <input type="hidden" name="_method" value="put"/>
</form>

 

另外一種方法是你可以使用ajax發送put,delete請求.

 

5. 靜態資源的URL重寫

   如上我們描述，現因爲將default servlet映射至/static/的子目錄，現我們訪問靜態資源將會帶一個/static/前綴.

   如 /foo.gif, 現在訪問該文件將是 /static/foo.gif.
   那如何避免這個前綴呢，那就是應用URL rewrite,現我們使用 http://tuckey.org/urlrewrite/, 重寫規則如下

 

<urlrewrite>
    <!-- 訪問jsp及jspx將不rewrite url,其它.js,.css,.gif等將重寫,如 /foo.gif => /static/foo.gif -->
    <rule>
        <condition operator="notequal" next="and" type="request-uri">.*.jsp</condition>
        <condition operator="notequal" next="and" type="request-uri">.*.jspx</condition>
        <from>^(/.*\..*)$</from>
        <to>/static$1</to>
    </rule>
</urlrewrite>

   另筆者專門寫了一個 RestUrlRewriteFilter來做同樣的事件，以後會隨着rapid-framework一起發佈. 比這個更加輕量級.

 

並且該代碼已經貢獻給spring,不知會不會在下一版本發佈